Scaling limits of dS vacua and the swampland

Self Cite

131

158

We propose an alternative refined de Sitter conjecture. It is given by a natural condition on a combination of the first and second derivatives of the scalar potential. We derive our conjecture in the same weak coupling, semi‐classical regime where the previous refined de Sitter conjecture was derived, using the same tools together with a few more assumptions that we discuss. We further test and constrain free parameters in our conjecture using data points of a classical type IIA supergravity setup. Interestingly, our conjecture easily accommodates slow‐roll single field inflation with a concave potential, favored by observations. The standard quintessence potential is in tension with our new conjecture, and we thus propose a different type of quintessence model.

g_{s}

, and a small number of O 6 .…”

Section: Testing the New Conjecturesupporting

confidence: 77%

Further Refining the de Sitter Swampland Conjecture

Andriot

Roupec

2019

Self Cite

131

158

“…This idea was recently put forward in [] when analysing known classical de Sitter solutions of type IIA supergravity: those appeared inconsistent with a stringy origin, because of these extra requirements. This question was then studied formally and exemplified for

p = 6

in []: the conclusions turned out consistent with conjecture , without being fully general. We investigate this question here for

p = 4, 5, 6

in a 10d approach and argue that one cannot conclude on a proof of conjecture with the tools developed so far.…”

Section: Conjecture 3: No Supergravity Solution With String Originmentioning

confidence: 91%

“…of order

N_{s}

and compensated in

R_{6}

by contributions of the other two structure constants listed in to generate a small

N_{f}^{2}

, as explained below . These open possibilities are to be contrasted with the discussion of section of []. The other flux equations do not allow us to be more conclusive regarding conjecture , because the same possibilities appear with structure constants, consistently with the required hierarchies.…”

Section: Conjecture 3: No Supergravity Solution With String Originmentioning

confidence: 93%

“…We combine appropriately the Equations , , , to be satisfied by de Sitter solutions. We read from , using that

F_{6 - p} \neq 0

3 g_{s} \frac{T_{10}}{p + 1} > - 2 {scriptR}_{6} \Rightarrow N_{s} > \frac{2}{3} \frac{N_{f}^{2}}{g_{s}} {((), \frac{L}{l_{s}})}^{7 - p} .

It is tempting to conclude from a proof of conjecture : indeed, taking

N_{f}^{2} \geq 1

, the requirements

L ≫ l_{s}

and

g_{s} ≪ 1

lead to a large right‐hand side since

p = 4, 5, 6

, forcing

N_{s}

to be larger than its bound; this point was made already for

p = 6

in []. For instance, a hierarchy of order 10 gives already

N_{s}

of at least 100, which is above the standard value of

2^{9 - p}

.…”

Section: Conjecture 3: No Supergravity Solution With String Originmentioning

confidence: 99%

“…In [] was proposed for

p = 6

the scaling

L / l_{s} \sim g_{s}^{- 1} \sim \sqrt{N_{s}}

for large

N_{s}

. This is different than considering as here a finite

N_{s}

of order 1.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Open Problems on Classical de Sitter Solutions

Andriot

2019

122

Classical 10d string backgrounds with a 4d de Sitter space‐time, D‐brane and orientifold sources, are commonly believed to satisfy the following: 1.There is no classical de Sitter solution with parallel sources. 2.Classical de Sitter solutions with intersecting sources are unstable. 3.Classical de Sitter solutions cannot have at the same time a large internal volume, a small string coupling, a bounded number of orientifolds and quantized fluxes. These three conjectures are of particular relevance to the swampland program, and if true, they challenge the connection of string theory to cosmology. We restrict here to a standard solution ansatz for which the problem is well‐defined, and we still fail to prove analytically any of these conjectures. While developing new tools and obtaining new constraints, we identify remaining corners of parameter space where counter‐examples to these conjectures could be found.

dS Supergravity from 10d

Каллош

Wrase

2018

Self Cite

102

We consider flux compactification of type II string theory with local sources on SU(3)‐structure manifolds. By adding pseudo‐calibrated anti‐Dp‐branes wrapped on supersymmetric cycles we generalize all existing models so that the effective d=4, N=1 supergravity now includes a nilpotent multiplet. We present a new dictionary between string theory models and Kähler potential K and superpotential W for these dS supergravities with a nilpotent multiplet and non‐linearly realized local supersymmetry. In addition to KKLT and LVS with uplifting D3¯‐branes, we have now new models with uplifting D5¯, D6¯, D7¯, D9¯‐branes. The new uplifting contribution to the supergravity potential due to Volkov‐Akulov supersymmetry is universal. As one application of our general result, we study classical flux compactifications of type IIA supergravity and find that a previously discovered universal tachyon is now absent.